CN119171026A

CN119171026A - Insulating sheet for battery, method for manufacturing the same, and battery module including the insulating sheet

Info

Publication number: CN119171026A
Application number: CN202410722573.9A
Authority: CN
Inventors: 梁承龙; 禹明希; 柳宝炅; 罗荷娜; 李载铉; 朴寭真
Original assignee: Samsung SDI Co Ltd
Current assignee: Samsung SDI Co Ltd
Priority date: 2023-06-19
Filing date: 2024-06-05
Publication date: 2024-12-20
Also published as: EP4517940A1; KR20240177076A; JP2025000551A; US20240421382A1

Abstract

The present invention relates to an insulating sheet for a battery, a method of manufacturing the same, and a battery module including the insulating sheet. Embodiments include an insulating sheet for a battery, the insulating sheet including an aerogel layer comprising aerogel and a coating configured to cover substantially an entire surface of the aerogel layer. The coating includes a flexible polymer and a flame retardant dispersed in the flexible polymer, and the coating has an elastic modulus of about 8MPa or less as measured according to ASTM D882. Embodiments also include a method of manufacturing the insulating sheet and a battery module including the insulating sheet.

Description

Insulating sheet for battery, method of manufacturing the same, and battery module including the same

Cross Reference to Related Applications

The present application claims the benefit of priority of korean patent application No. 10-2023-0078088 filed in the korean intellectual property office on day 19 of year 2023, the entire disclosure of which is incorporated herein by reference.

Technical Field

Example embodiments relate to an insulating sheet for a battery, a method of manufacturing the same, and a battery module including the insulating sheet.

Background

A secondary battery is an electric power storage system that converts electric energy into chemical energy, stores the chemical energy, and provides high energy density. Secondary batteries are rechargeable compared to primary batteries that are not rechargeable, and are generally widely used in Information Technology (IT) devices such as smart phones, mobile phones, laptop computers, and tablet computers. Electric vehicles are increasingly being interested in order to reduce or prevent environmental pollution, and high-capacity secondary batteries are generally used in electric vehicles. Secondary batteries generally exhibit desirable characteristics such as, for example, high density, high output, and stability.

When a plurality of high-capacity battery cells are included, as in a lithium ion secondary battery, one battery cell may overheat and may enter thermal runaway for various reasons, which may adversely affect other battery cells adjacent thereto, so it is desirable to thermally isolate the adjacent battery cells from each other.

Conventionally, plates or insulating resin sheets are positioned between the battery cells to separate and insulate the adjacent battery cells from each other.

Disclosure of Invention

Example embodiments provide an insulating sheet for a battery, which has desirable, advantageous, or improved thermal insulation, fire resistance, and flame retardancy or nonflammability to reduce or inhibit the propagation of heat in a battery cell to a battery cell adjacent thereto due to thermal runaway of the battery cell, a method of manufacturing the same, and a battery module including the same.

Example embodiments include an insulating sheet for a battery, the insulating sheet including an aerogel layer comprising an aerogel and a coating configured to cover substantially an entire surface of the aerogel layer, wherein the coating includes a flexible polymer and a flame retardant dispersed in the flexible polymer, and the coating has an elastic modulus of about 8MPa or less as measured according to ASTM D882.

Aerogels can have Brulol, emmett, and Taylor (BET) specific surface areas in the range of about 500m ²/g～1,000m²/g.

The aerogel layer can further comprise a fibrous support and a functional material comprising a binder, a dispersant, or a combination thereof.

The fiber support may include at least one of natural fibers, silica fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers.

The binder may comprise an aqueous polymeric binder.

The dispersant may be or include at least one of a surfactant, a silane coupling agent, and a phosphate salt.

Aerogel may be included in a range of about 10wt% to 90wt%, fibrous support may be included in a range of about 5wt% to 70wt%, and functional material may be included in a range of about 0.5wt% to 20wt%, based on the total amount of aerogel layers.

The flexible polymer may be at least one of a fluorinated polymer, a polyurethane-based polymer, a polyolefin-based polymer, and a silicone-based polymer.

The flame retardant may be at least one of an inorganic flame retardant, a phosphorus-based flame retardant, a nitrogen compound-based flame retardant, a silicone-based flame retardant, a melamine-based flame retardant, a halogen-based flame retardant, and a polyol-based flame retardant.

The flame retardant may include at least one of a phosphorus-based flame retardant and a polyol-based flame retardant.

The flame retardant may include a phosphorus flame retardant and a polyol flame retardant in a weight ratio ranging from about 1:0.1 to 1:0.5.

The content of the flame retardant may be in the range of about 1wt% to 25wt% based on the total amount of the coating.

The coating may not include a filler.

The thickness of the coating layer may be about 20% or less of the total thickness of the insulating sheet for the battery.

The flexible polymer may be or include at least one of a polyurethane-based polymer and a silicone-based polymer, and the flame retardant may be at least one of a polyol-based flame retardant and a phosphorus-based flame retardant.

Another example embodiment includes a method of making an insulating sheet for a battery, the method comprising forming an aerogel layer comprising an aerogel and forming a coating to cover substantially an entire surface of the aerogel layer, wherein the coating comprises a flexible polymer and a flame retardant dispersed in the flexible polymer, and the coating has an elastic modulus of about 8MPa or less as measured according to ASTM D882.

Further example embodiments include a battery module including a plurality of battery cells and an insulating sheet between the plurality of battery cells.

Drawings

The accompanying drawings, which are incorporated in the specification, illustrate example embodiments and, together with the detailed description of the example embodiments, serve to further explain the technical ideas of the present disclosure, and the present disclosure is not to be construed as limited to what is shown in these drawings. In the drawings:

fig. 1 is a schematic view illustrating an insulating sheet for a battery according to an example embodiment formed between a plurality of battery cells;

Fig. 2 is a schematic view showing a sectional structure of an insulating sheet for a battery according to the example embodiment of fig. 1, and

Fig. 3 and 4 are schematic views each showing a sectional structure of an insulating sheet according to a comparative example.

Detailed Description

Hereinafter, example embodiments will be described in detail so that those skilled in the art can easily implement the example embodiments. However, the example embodiments may be embodied in many different forms and are not limited to the example embodiments described herein.

When the term "about" or "substantially" is used in this specification in connection with a numerical value, it is intended that the relevant numerical value includes tolerances of + -10% around the numerical value. Also, when referring to percentages in this specification, those percentages are based on concentration or weight, such as concentration percentages or weight percentages. When a range is indicated, the range includes all values therebetween, such as 0.1% increments.

Insulating materials, which are a material that impedes or prevents heat flow from higher temperatures to lower temperatures, are used not only in refrigerators, freezers and buildings, but also in various other industries including the aircraft, electronics and automotive industries.

The insulating material desirably and advantageously has sufficient thermal insulation by low thermal conductivity and mechanical strength to maintain thermal insulation over time.

Aerogels, which are transparent or translucent advanced materials having a nanoporous structure, exhibit substantially low density and low thermal conductivity, are highly desirable as insulation materials and are considered to be a highly efficient super insulation material that can be used in a variety of industrial applications.

An important advantage of aerogels is that aerogels have lower thermal conductivities than conventional organic insulating materials such as, for example, polystyrene foam, and aerogels can address or overcome key weaknesses of organic insulating materials such as, for example, fire vulnerability and hazardous gases generated upon fire.

An insulating sheet for a battery according to example embodiments may include an aerogel layer including aerogel and a coating layer configured to cover substantially an entire surface of the aerogel layer, wherein the coating layer may include a flexible polymer and a flame retardant dispersed in the flexible polymer, and an elastic modulus of the coating layer may be about 8MPa or less, measured according to ASTM D882.

The insulating sheet for a battery having the above-described structure may have desired, advantageous, or improved thermal insulation, fire resistance, and flame retardancy or nonflammability, thereby reducing or inhibiting heat and flame in one battery cell from propagating to a battery cell adjacent thereto due to thermal runaway of the battery cell. The insulating sheet for a battery may have desired, advantageous or improved compressibility, mechanical strength and dimensional stability, and may reduce or prevent the aerogel layer from falling off due to external impact, thereby improving workability and reducing or preventing instrument contamination.

In an example embodiment, the aerogel can have a BET specific surface area in the range of about 500m ²/g～1,000m²/g. For example, aerogels can have BET specific surface areas in the range of about 500m ²/g～950m²/g、550m²/g～950m²/g or 600m ²/g～900m²/g. Since the aerogel having the BET specific surface area value in the above range is included, the diffusion of aerogel particles can be reduced or prevented, and thermal insulation can be improved.

The particle size of the aerogel may be in the range of about 5 μm to 200 μm, 10 μm to 100 μm, or 20 μm to 60 μm. Since the aerogel having the particle size within the above range is included, thermal insulation can be improved, and thus, heat propagation between the plurality of battery cells can be delayed.

The aerogel may be present in an amount ranging from about 10wt% to 90wt%, 30wt% to 70wt%, or 40wt% to 60wt% based on the total amount of the aerogel layer. When an aerogel layer comprising an aerogel within the above-described ranges is included, thermal insulation of the insulating sheet for the battery may be desirable or advantageous.

In example embodiments, the aerogel layer can further comprise a fibrous support and a functional material comprising a binder, a dispersant, or a combination thereof.

The fiber support may be included in the aerogel layer, whereby durability of an insulating sheet for a battery formed using the fiber support may be improved.

The fiber support may include fibers that serve as a support made of or including a common insulating material. For example, the fiber support may be or include at least one of natural fibers, silica fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers. As an example, the fibrous support may include, but is not limited to, glass fibers. By way of example, glass fibers may include, but are not limited to, glass wool.

The natural fibers may be or include, for example, at least one of hemp, jute, flax, coir, kenaf, and cellulose.

Mineral fibers may include, for example, at least one of basalt, quartzite, alumina, silica, slag, and rock.

The polymer fiber may be, for example, at least one of nylon, polyimide, polyamide, polybenzimidazole, polybenzoxazole, polyamideimide, polyethylene terephthalate, polybutylene terephthalate, polyester, polyethylene (PE), and polypropylene (PP). By way of example, the polymer fiber may be, but is not limited to, at least one of polyimide, polyamide, and polybenzimidazole.

The fiber support may be in the form of, for example, wool or chopped strands, but is not limited thereto.

The average particle size D50 of the fiber support may be, for example, in the range of about 0.1 μm to 20 μm, 0.1 μm to 15 μm, 0.1 μm to 5 μm, 1 μm to 15 μm, or 3 μm to 10 μm. By including the fiber support having the average particle size within the above range, the structure of the aerogel layer can be hardened and the manufacturing cost can be reduced.

The average particle size D50 may be measured, for example, using a laser diffraction method or a Scanning Electron Microscope (SEM), wherein the average particle size D50 of the particles may be defined as the particle size at 50% of the particle size distribution (the particle size corresponds to the cumulative 50% of the volume of the particle size distribution).

The content of the fibrous support may be in the range of about 5wt% to 70wt%, 25wt% to 60wt%, or 30wt% to 50wt% based on the total amount of the aerogel layer. When an aerogel layer including the fiber support within the above range is used to manufacture an insulating sheet for a battery, durability can be improved.

The binder may comprise an aqueous polymeric binder. For example, the aqueous polymer binder may be at least one of an aqueous polymer, an anionic water-soluble polymer, a cationic water-soluble polymer, and a water-dispersible polymer.

The aqueous polymer may be, for example, but not limited to, at least one of polyvinyl alcohol, polyethylene oxide, polyacrylamide, and polyvinylpyrrolidone.

The anionic water-soluble polymer may be a polymer having a functional group of at least one of carboxylic acid, sulfonic acid, sulfuric acid ester, phosphoric acid ester, and salts thereof. For example, the anionic water-soluble polymer may be or include a polymer having carboxylic acid groups, and may include, but is not limited to, polymaleic acid as an example.

The cationic water-soluble polymer may be a polymer having a functional group of at least one of amine, ammonium, phosphonium, sulfonium, and salts thereof. For example, the cationic water-soluble polymer may be or include a polymer having amine groups, and may be, but is not limited to, at least one of a polyvinylamine and a polyamine, as examples.

The water-dispersible polymer may be, but is not limited to, at least one of a water-dispersible polyurethane and a water-dispersible polyester.

The binder may include an aqueous polymer and a water-dispersible polymer. For example, the binder may include an aqueous polymer having binder properties and dispersion properties, and a water-dispersible polymer having fire resistance. As an example, the binder may include polyvinyl alcohol and water-dispersible polyurethane.

The weight ratio of the aqueous polymer to the water-dispersible polymer may be in the range of about 1:1 to 1:5, 1:1 to 1:4, or 1:2 to 1:3. When the weight ratio of the aqueous polymer to the water-dispersible polymer is within the above range, the fire resistance and mechanical properties of the insulating sheet can be further improved in addition to the thermal insulation, dust formation and compressibility of the insulating sheet.

The binder may be present in an amount ranging from about 0.5wt% to 20wt%, 2wt% to 15wt%, or 8wt% to 15wt% based on the total amount of the aerogel layer. An insulating sheet for a battery including an aerogel layer containing a binder within the above-described range may have improved dust formation.

The dispersant may be or include at least one of a surfactant, a silane coupling agent, and a phosphate salt. For example, the dispersing agent may include, but is not limited to, at least one of a nonionic surfactant, an anionic surfactant, an amphoteric surfactant, a natural surfactant (such as lecithin), and a phosphate ester.

Further inclusion of a dispersant can further improve the dispersion of the aerogel during the manufacture of the aerogel layer, resulting in uniform dispersion of the fibrous support and the aerogel.

The content of the dispersant may be in the range of about 0.1wt% to 6wt%, 0.1wt% to 5wt%, or 0.1wt% to 3wt% based on the total amount of the aerogel layer. When the dispersing agent is included in the above range, the aerogel layer can be manufactured at low cost, and an insulating sheet having desired, improved or advantageous thermal insulation, uniformity and dust-forming properties can be manufactured using the aerogel layer.

In example embodiments, the binder and the dispersant may be included in a weight ratio ranging from about 1:0.001 to 1:0.67, 1:0.001 to 1:0.5, or 1:0.001 to 1:0.3. Mixing the binder and dispersant in any of the above ranges by weight can result in a more uniform dispersion of the aerogel in the aerogel layer.

In an example embodiment, the fibrous support may be included in a range of about 25wt% to 60wt%, the aerogel may be included in a range of about 30wt% to 70wt%, and the binder may be included in a range of about 2wt% to 15wt%, based on the total amount of the aerogel layer.

As an example, the fibrous support may be included in a range of about 30wt% to 50wt%, the aerogel may be included in a range of about 40wt% to 60wt%, and the binder may be included in a range of about 8wt% to 15wt%, based on the total amount of the aerogel layer. When the aerogel layer is formed within any of the above ranges, it is possible to achieve desired, improved, or advantageous thermal insulation while improving durability, and it is possible to improve adhesion between the fiber support and the aerogel, thereby reducing or preventing dust generation.

In an example embodiment, the fibrous support may be included in a range of about 25wt% to 60wt%, the aerogel may be included in a range of about 30wt% to 70wt%, the binder may be included in a range of about 2wt% to 15wt%, and the dispersant may be included in a range of about 0.1wt% to 3wt%, based on the total amount of the aerogel layer.

As an example, the fibrous support may be included in a range of about 30wt% to 50wt%, the aerogel may be included in a range of about 40wt% to 60wt%, the binder may be included in a range of about 5wt% to 10wt%, and the dispersant may be included in a range of about 0.1wt% to 2wt%, based on the total amount of the aerogel layer. When the aerogel layer is formed within the above ranges, desired, improved, or advantageous thermal insulation can be achieved while improving durability, and adhesion between the fiber support and the aerogel can be improved, thereby reducing or preventing dust generation.

The flexible polymer included in the coating layer is not particularly limited as long as the polymer is flexible. For example, the flexible polymer may be at least one of a fluorinated polymer, a polyurethane-based polymer, a polyolefin-based polymer, and a silicone-based polymer.

The fluorinated polymer may be, for example, at least one of Polytetrafluoroethylene (PTFE), soluble Polytetrafluoroethylene (PFA), fluorinated ethylene propylene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), and Polychlorotrifluoroethylene (PCTFE). The fluorinated polymer may be a material that is flexible and is itself a flame retardant.

The polyurethane-based polymer is not particularly limited as long as the polyurethane-based polymer is a general polyurethane produced by polymerization of a polyol and a polyisocyanate. The polyol may be, for example, a general polyol used for manufacturing polyurethane, and may be at least one of polyether polyol, polyester polyol, polyamide polyol, polyester amide polyol, polythioether polyol, polycarbonate polyol, polyacetal polyol, polyolefin polyol, polysiloxane polyol, acrylic polyol, and silicone polyol. The polyisocyanate may include, for example, a general polyisocyanate used for manufacturing polyurethane, and may be or include at least one of toluene diisocyanate, isophorone diisocyanate, cyclohexane-1.4-diisocyanate, 4-dicyclohexylmethane diisocyanate, 4-bis (aminocyclohexyl) methane hexamethylene diisocyanate, 1, 4-phenylene diisocyanate, 4-diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, trimethylhexamethylene diisocyanate, and norbornane diisocyanate.

The polyolefin-based polymer may be, for example, at least one of polyethylene, polypropylene, polybutene, polypentene, polyvinylidene fluoride, and polymethyl methacrylate.

The silicone-based polymer may be, for example, at least one of silicone elastomer, polydimethylsiloxane, polymethylethylsiloxane, polydiethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, and polyethylphenylsiloxane.

The flexible polymer may be present in an amount ranging from about 75wt% to 99wt%, 90wt% to 97wt%, or 94wt% to 97wt% of the total amount of the coating. By forming a coating layer including a flame retardant within any of the above ranges on a surface of an aerogel layer having desired, improved, or advantageous thermal insulation, an insulating sheet for a battery may have not only thermal insulation but also fire resistance and flame retardancy or nonflammability.

The coating may further comprise a flame retardant. The type of the flame retardant is not particularly limited, and the flame retardant may be, for example, at least one of an inorganic flame retardant, a phosphorus-based flame retardant, a nitrogen-based flame retardant, a silicone-based flame retardant, a melamine-based flame retardant, a halogen-based flame retardant, and a polyol-based flame retardant.

Inorganic flame retardants may include metal oxides and metal hydroxides. For example, the inorganic flame retardant may be, but is not limited to, at least one of silicon oxide, magnesium hydroxide, aluminum hydroxide, antimony oxide, sodium carbonate, zinc oxide, iron oxide, tin oxide, zinc borate, and calcium borate.

The phosphorus-based flame retardant may include a general phosphorus-containing flame retardant. For example, the phosphorus-based flame retardant may include, but is not limited to, at least one of phosphates, phosphonates, phosphinates, phosphine oxides, phosphazenes, and ammonium salts thereof.

The phosphorus-based flame retardant may include ammonium phosphate or ammonium phosphate having two or more hydroxyl groups at the end of the functional group. The use of phosphorus-based flame retardants having multifunctional hydroxyl groups can provide desirable, improved, or advantageous flame retardancy. By way of example, phosphorus-based flame retardants may include, but are not limited to, ammonium phosphate or monoammonium phosphate.

The nitrogen compound-based flame retardant may be, but is not limited to, at least one of aliphatic amine compounds, aromatic amine compounds, nitrogen-containing bicyclic compounds, cyanide compounds, ammonium hydroxide, aliphatic amides, aromatic amides, urea, and thiourea.

The silicone-based flame retardant may be a silicone resin or a silicone oil. The silicone resin may include a resin having an RSiO structure, wherein R may indicate an alkyl group having 1 to 10 carbon atoms (such as methyl, ethyl, or propyl), an aryl group, or a substituent in which at least one hydrogen of the alkyl group and the aryl group is substituted with a vinyl group. The silicone oil may be, but is not limited to, at least one of polydimethylsiloxane and modified polydimethylsiloxane in which at least one methyl group of a side chain or a terminal of polydimethylsiloxane is modified with at least one of hydrogen, alkyl (other than methyl), cyclohexyl, phenyl, benzyl, epoxy, polyether, carboxyl, mercapto, chloroalkyl, alkyl alcohol ester, alcohol, allyl, vinyl, and trifluoromethyl.

The melamine based flame retardant may be, but is not limited to, at least one of melamine phosphate, di (melamine) phosphate, melamine pyrophosphate, and melamine cyanurate.

Any halogen-based compound capable of being used as a flame retardant may be used as the halogen-based flame retardant without limitation. For example, the halogen-based flame retardant may be, but is not limited to, at least one of decabromodiphenyl ether, decabromodiphenyl ethane, tetrabromobisphenol a epoxy oligomer, octabromotrimethylphenyl indane, ethylene-bis-tetrabromophthalimide, tris (tribromophenol) triazine, and brominated polystyrene.

The polyol flame retardant may be, for example, at least one of pentaerythritol, dipentaerythritol, trimethylolpropane, and ethylene glycol. As an example, the polyol flame retardant may be dipentaerythritol.

Flame retardants may include phosphorus-based flame retardants and polyol-based flame retardants, in which case flame retardancy can be achieved without releasing harmful substances.

The flame retardant may include a phosphorus flame retardant and a polyol flame retardant in a weight ratio in a range of about 1:0.1-1:0.5, 1:0.1-1:0.4, 1:0.15-1:0.35, or 1:0.15-1:0.25. When the phosphorus-based flame retardant and the polyol-based flame retardant are mixed within the above-described range, the elastic modulus of the coating layer may be desired, improved or advantageous, and the flame retardancy of the insulating sheet may be improved.

The content of the flame retardant may be in the range of about 1wt% to 25wt%, 3wt% to 10wt%, or 3wt% to 6wt% based on the total amount of the coating. By forming a coating layer including a flame retardant within any of the above ranges on a surface of an aerogel layer having desired, improved, or advantageous thermal insulation, an insulating sheet for a battery may have not only thermal insulation but also fire resistance and flame retardancy or nonflammability.

The coating may not include a filler. The filler may be, but is not limited to, at least one of fumed silica, diatomaceous earth, halloysite, carbon nanotubes, perlite, silica, alumina, barium sulfate, mud, talc, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, and vermiculite, for example.

The aerogel layer may be hexahedral having an upper surface, a lower surface, and a boundary side surface between the upper surface and the lower surface, and a coating layer may be formed to cover substantially the entire surface of the aerogel layer.

As an example, the coating may cover substantially the entire surface of the aerogel layer including the upper surface, the lower surface, and the boundary side surfaces of the aerogel layer. An insulating sheet for a battery having a coating layer formed to cover substantially the entire surface of the aerogel layer as described above may be disposed between a plurality of battery cells, wherein an upper surface and a lower surface of the insulating sheet for a battery may face the plurality of battery cells disposed on opposite side surfaces of the insulating sheet, respectively. A coating layer having flame retardancy may be formed on substantially the entire surface of an insulating sheet for a battery, which may reduce or prevent the insulating sheet from burning, and may block or block flames in the event of thermal runaway of one battery cell, thereby reducing or inhibiting the propagation of flames to the battery cells adjacent thereto, and effectively reducing or preventing the propagation of flames in a battery module having a plurality of battery cells.

The thickness of the coating layer may be in the range of about 20% or less, 1% to 20%, 5% to 17%, or 8% to 12% of the total thickness of the insulating sheet for a battery. By forming the coating layer to have a thickness within any of the above ranges, the insulating sheet for a battery may have desired, improved or advantageous thermal insulation and flame retardancy or nonflammability.

The coating may include a flexible polymer and a flame retardant dispersed in the flexible polymer, wherein the flexible polymer may be at least one of a polyurethane-based polymer and a silicone-based polymer, and the flame retardant may be at least one of a polyol-based flame retardant and a phosphorus-based flame retardant. In this case, falling off and diffusion of the aerogel layer, which may be caused by external impact, may be hindered or prevented, workability may be improved, contamination of the instrument may be reduced or prevented, and desired, improved or advantageous thermal insulation and flame retardancy or nonflammability may be achieved.

In an example embodiment, the coating may have an elastic modulus of about 8MPa or less as measured according to ASTM D882. For example, the elastic modulus of the coating, measured according to ASTM D882, may be in the range of about 1mpa to 8mpa, 3mpa to 7mpa, or 3mpa to 5 mpa.

The method of manufacturing an insulation sheet for a battery according to example embodiments may include forming an aerogel layer including aerogel and forming a coating layer to cover substantially the entire surface of the aerogel layer, wherein the coating layer may include a flexible polymer and a flame retardant dispersed in the flexible polymer, and an elastic modulus of the coating layer may be about 8MPa or less as measured according to ASTM D882.

In an example embodiment, forming the aerogel layer can include mixing a solvent with a functional material including a binder, a dispersant, or a combination thereof to produce a solvent mixture, mixing the solvent mixture with an aerogel to produce an aerogel mixture, and mixing the aerogel mixture with a fibrous support to produce an aerogel composition.

In mixing the solvent with the functional material to produce a solvent mixture, the solvent may be mixed with the binder, or the solvent may be mixed with the binder and the dispersant.

The solvent may be at least one of a polar solvent and a nonpolar solvent.

The polar solvent may be at least one of water and an alcohol solvent.

The water may be, for example, at least one of purified water and deionized water.

The alcohol solvent may be, for example, but not limited to, at least one of methanol, ethanol, propanol, pentanol, butanol, hexanol, ethylene glycol, propylene glycol, diethylene glycol, and glycerol.

The nonpolar solvent may include a hydrocarbon solvent. For example, the hydrocarbon solvent may be at least one of hexane, pentane, heptane, toluene, and benzene, and may be, but is not limited to, an alkane solvent (such as hexane) or a mixture including an alkane solvent.

The solvent may include water. The use of water as a solvent can effectively reduce raw material costs and post-treatment costs. However, when water is used as a solvent, the water may not satisfactorily mix with the aerogel because the aerogel is hydrophobic. In example embodiments, the aerogel may be uniformly dispersed by controlling the design of the mixing process, the mixing conditions, the addition of the binder and the dispersant, and the amounts of the binder and the dispersant. This uniform dispersion of aerogel in the composition can form a thin thickness insulating sheet for a battery with desirable or improved thermal insulation, durability, and dust formation without the use of a large amount of binder.

The solvent may be included such that the weight ratio of solvent to the total amount of solids in the aerogel composition is in the range of about 1:1 to 1:90. For example, the weight ratio of solvent to total solids in the aerogel composition can be in the range of about 1:50 to 1:70, 1:20 to 1:30, or 1:2 to 1:10. By controlling the weight ratio of solvent to the total amount of solids in the aerogel composition within the above-described range, dispersibility, coatability, and phase stability can be compatible.

The detailed description of the binder and dispersant may be similar or identical to the description above.

In mixing the solvent mixture with the aerogel to produce the aerogel mixture, the detailed description of the aerogel can be similar or identical to the description above.

In mixing the aerogel mixture with the fibrous support to produce the aerogel composition, the detailed description of the fibrous support can be similar or identical to the description above.

In each of mixing a solvent with a functional material including a binder, a dispersant, or a combination thereof to produce a solvent mixture, mixing the solvent mixture with an aerogel to produce an aerogel composition, and mixing the aerogel mixture with a fibrous support to produce an aerogel composition, mixing can be performed using a mixer. For example, mixers may include, but are not limited to, planetary mixers, planetary Despa ^TM (PD) mixers, thinky ^TM mixers, and C mixers.

As an example, a planetary mixer can be used to mix the solvent mixture with the aerogel. Mixing the solvent mixture with the aerogel using a planetary mixer can allow the aerogel to be substantially uniformly dispersed in the solvent.

A planetary mixer may be a device that may be used to mix or agitate different substances in order to produce a homogeneous mixture. The planetary mixer may include a blade capable of planetary motion.

In an example embodiment, the planetary mixer may include at least one of one or more planetary blades and one or more high-speed dispersion blades. As an example, a planetary mixer may include at least one planetary blade and at least one high speed dispersion blade.

Each of the planetary blades and the high-speed dispersion blades may be configured to continuously rotate about its axis. The rotational speed may be expressed in revolutions per minute (rpm).

In an example embodiment, the planetary mixer may include a first blade and a second blade having different axes of rotation. For example, the first blade may be a low speed blade and the second blade may be a high speed blade. Low speed and high speed refer to the relative rotational speed between the first blade and the second blade. As an example, the first blade may be an open blade and the second blade may be a Despa ^TM blade.

The rotational speed of the first blade may be in the range of, for example, about 10rpm to 100rpm, 10rpm to 60rpm, or 30rpm to 70 rpm. The second blade may be rotated at a speed of, for example, about 100rpm to 2000rpm 100 to 1000rpm, 300 to 1700rpm, or 500 to 1700 rpm.

When the functional material is added to and mixed with the solvent, the rotational speed of the first blade may be in the range of about 10rpm to 60rpm, 20rpm to 50rpm, or 30rpm to 40rpm, and the rotational speed of the second blade may be in the range of about 300rpm to 1700rpm, 600rpm to 1000rpm, or 700rpm to 800 rpm. As described above, when the solvent and the functional material are mixed with each other, a solvent mixture in which the binder, the dispersant, or a combination thereof is substantially uniformly dispersed can be manufactured to facilitate mixing the aerogel in a subsequent process.

When the solvent mixture and the aerogel powder are mixed with each other, the rotation speed of the first blade of the mixer may be in the range of about 30rpm to 70rpm, 40rpm to 70rpm, or 60rpm to 70rpm, and the rotation speed of the second blade may be in the range of about 500rpm to 1700rpm, 600rpm to 1600rpm, or 800rpm to 1500 rpm. As described above, when aerogel powder is added to and mixed with a solvent mixture, the aerogel powder can be hindered or prevented from agglomerating together to induce a substantially uniform dispersion.

When the aerogel mixture and the fiber support are mixed with each other, the rotational speed of the first blade of the mixer may be in the range of about 10rpm to 60rpm, 20rpm to 50rpm, or 30rpm to 40rpm, and the rotational speed of the second blade may be in the range of about 300rpm to 1700rpm, 400rpm to 1500rpm, or 800rpm to 1200 rpm. Mixing the aerogel mixture with the fibrous support as described above can remove air bubbles in the composition, control viscosity, and facilitate dispersion of the fibrous support in the substantially uniformly dispersed aerogel such that the aerogel surrounds the fibrous support in the composition. A binder may be present between the aerogel and the fibrous support to improve the bond between the aerogel and the fibrous support.

In example embodiments, the aerogel layer may be formed in a single-layer structure or a multi-layer structure. When the aerogel layer is formed as a multi-layered structure, the aerogel layer may be formed to have about 2 to 10 layers, 2 to 7 layers, or 2 to 5 layers.

The aerogel layer can be formed, for example, by extruding, coating, or casting the aerogel composition using conventional methods.

By forming the aerogel layer using the method according to example embodiments, thermal insulation and durability of the insulating sheet for a battery can be improved, and when the insulating sheet for a battery is manufactured or installed in a device, the aerogel can be hindered or prevented from falling off and dust can be generated.

In example embodiments, forming the coating may be performed by dipping the aerogel layer in a coating forming solution to cover two or more surface portions of the entire surface of the aerogel layer.

The coating-forming solution may include a flexible polymer or a flexible polymer and a flame retardant. The detailed description of the flexible polymer and the flame retardant may be the same as described above.

When the aerogel layer is immersed in the coating-forming solution, the coating-forming solution may be dispersed or dissolved using an appropriate solvent, in which case the viscosity may be controlled to form a uniform coating.

In example embodiments, the aerogel layer may be immersed in the coating forming solution, and may be dried at a temperature higher than the boiling point of the solvent to manufacture the insulating sheet for a battery according to example embodiments.

In example embodiments, the method may further include crosslinking the aerogel layer after immersing the aerogel layer in the coating-forming solution. Crosslinking can improve the cohesion between the aerogel layer and the coating.

The crosslinking method is not particularly limited, and for example, a thermal crosslinking method and an Ultraviolet (UV) crosslinking method may be used.

Thermal crosslinking may be performed at a temperature in the range of about 25 ℃ to 150 ℃ for 10 seconds to 30 minutes.

UV crosslinking may be performed by irradiating with UV light for about 10 seconds to 5 minutes.

For ultraviolet crosslinking, the coating-forming solution may further include a crosslinking agent.

The crosslinking agent is not particularly limited, and may be, for example, at least one of a polyfunctional acrylate-based compound, an isocyanate-based compound, an epoxy-based compound, an aziridine-based compound, and a metal chelate-based compound.

The multifunctional acrylate compound may be, for example, at least one of pentaerythritol tri/tetra acrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate, and hexamethylene diacrylate.

The isocyanate-based compound may be, for example, at least one of toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, hetero-diisocyanate, tetramethylxylene diisocyanate, and naphthalene diisocyanate.

The epoxy compound may be, for example, at least one of ethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, N' -tetraglycidyl ethylenediamine, and glycerol diglycidyl ether.

The aziridine compound may be, for example, at least one of N, N ' -toluene-2, 4-bis (1-aziridine carbonyl), N ' -diphenylmethane-4, 4' -bis (1-aziridine carbonyl), triethylenemelamine, bis-isophthaloyl-1- (2-methylaziridine), and tri-1-aziridinyl phosphine oxide.

The metal chelate compound may include, for example, a compound in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium or vanadium is coordinated with acetylacetone or ethylacetylacetone.

For Ultraviolet (UV) crosslinking, a photoinitiator may be further included.

The photoinitiator is not particularly limited, and may be, for example, at least one of benzophenone, acetophenone, chloroacetophenone, diethoxyacetophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin acetic acid, benzoin methyl acetate, benzoin dimethyl ketal, 2, 4-diethylthioxanthone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, diacetyl, β -chloroanthraquinone, thioxanthone, and 2-ethylanthraquinone.

In example embodiments, the substrate may be disposed on one surface or the opposite surface of the insulating sheet for the battery. One surface may refer to an upper surface or a lower surface of an insulating sheet for a battery on which a coating layer is formed, and the opposite surfaces may refer to an upper surface and a lower surface of an insulating sheet for a battery on which a coating layer is formed.

For example, the substrate may include, but is not limited to, a resin, a metal, an inorganic material other than a metal, or a composite thereof. The substrate may be in the form of, but is not limited to, a film, a membrane, a sheet, and the like.

The resin may include, for example, at least one of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyamide.

The metal may include, for example, at least one of copper, nickel, cobalt, iron, chromium, vanadium, palladium, ruthenium, rhodium, molybdenum, tungsten, iridium, silver, gold, and platinum. When a substrate made of or including the above metal is used, the substrate may be subjected to a corrosion-resistant treatment or an insulating treatment as needed.

The inorganic material other than metal may include at least one of calcium carbonate (CaCO ₃), talc, and mica.

As an example, the substrate may include an inorganic material, and as another example, the substrate may include mica. In this case, thermal insulation, durability, and the like of the insulating sheet can be improved.

The battery module according to the example embodiment may include a plurality of battery cells and an insulating sheet for a battery disposed between the plurality of battery cells.

The battery cell may be a secondary battery cell. The secondary battery cell may be, for example, a lithium secondary battery. Lithium secondary batteries may be manufactured in various forms such as lithium ion batteries, all-solid-state batteries, or lithium metal batteries. For example, a lithium secondary battery may have a structure in which a positive electrode plate having a positive electrode active material applied thereto and a negative electrode plate having a negative electrode active material applied thereto are arranged with a separator interposed therebetween, and the lithium secondary battery may be accommodated in a battery case together with an electrolyte in a sealed state to constitute a secondary battery cell. The secondary battery cells may be classified as, for example, cylindrical secondary battery cells, prismatic secondary battery cells, or pouch-shaped secondary battery cells according to the shape of the battery case, and a plurality of secondary battery cells may be connected in series or in parallel with each other to constitute a battery module.

The secondary battery cell may require high stability, for example, when overcharged, decomposition and other side reactions of the positive electrode active material or electrolyte may occur, whereby heat may be emitted from the secondary battery cell, resulting in explosion of the secondary battery cell.

In example embodiments, an insulating sheet including a coating layer formed to cover a portion or an entirety of a surface of the insulating sheet is disposed between the battery cells, whereby the insulating sheet may have desired, advantageous, or improved thermal insulation, fire resistance, and flame retardancy, or nonflammability, so heat and flame in the battery cells due to thermal runaway of the battery cells may be suppressed from being propagated to the battery cells adjacent thereto.

Fig. 1 is a schematic view illustrating a plurality of battery cells and an insulating sheet for a battery disposed between the battery cells according to an example embodiment.

Referring to fig. 1, an insulating sheet 100 for a battery according to an example embodiment may be disposed between a plurality of battery cells 200 included in a battery module. When the insulating sheet 100 for a battery according to the example embodiment is formed between the plurality of battery cells 200, it is possible to provide a battery module capable of previously blocking or blocking flames in the event of thermal runaway of one battery cell, thereby substantially suppressing propagation of flames to another battery cell with a higher safety level, and a battery pack including the same.

Fig. 2 is a schematic view showing a cross-sectional structure of an insulating sheet for a battery according to an example embodiment.

Referring to fig. 2, the insulating sheet 100 for a battery may be formed to have a structure including an aerogel layer 110 and a coating layer 120 formed on substantially the entire surface of the aerogel layer 110, the substantially entire surface of the aerogel layer 110 including an upper surface 111, a lower surface 112, and a boundary side surface 113 between the upper surface 111 and the lower surface 112.

Hereinafter, embodiments will be described. However, the following examples are only intended to illustrate or describe the present disclosure, and should not be construed as limiting the present disclosure. Details not described herein can be sufficiently inferred by those skilled in the art, so descriptions thereof will be omitted.

(Production of insulating sheet for Battery)

Example 1

1. Manufacture of aerogel layers

The solvent mixture was produced by adding polyvinyl alcohol (SIGMA ALDRICH) as a binder to deionized water as a solvent, and mixing it at 30rpm using an open blade and at 700rpm using a Despa ^TM blade. Subsequently, aerogel having a BET value of 800m ²/g was added to the solvent mixture and mixed at 70rpm using an open blade and at 1500rpm using a Despa ^TM blade to produce an aerogel mixture. Aerogel compositions were made by adding glass wool to the aerogel mixture and mixing it at 30rpm using an open blade and at 1200rpm using a Despa ^TM blade. Planetary mixers (DNTEK, PT-005) were used for mixing.

The solid content of the aerogel composition produced was found to be 50wt% aerogel, 40wt% glass wool and 10wt% polyvinyl alcohol.

An aerogel layer is formed using the manufactured aerogel composition.

2. Manufacture of insulating sheet for battery

The aerogel layer produced is immersed in a coating forming solution to form a coating on substantially the entire surface of the aerogel layer. The coating forming solution was manufactured to include 94.8wt% polyurethane (Shenzhen Jian chemical Co., PU solution), 4wt% ammonium phosphate (Merck) and 1.2wt% dipentaerythritol (Merck) as flame retardants.

After immersing the aerogel layer in the coating forming solution, the aerogel layer is dried to produce an insulating sheet for a battery having a coating layer formed on substantially the entire surface of the aerogel layer. The total thickness of the insulating sheet for a battery was 3mm, the thickness of the aerogel layer was 2.7mm, and the thickness of the coating layers on the upper surface, the lower surface, and the boundary side surface of the aerogel layer was 0.15mm.

Example 2

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that a coating forming solution including 94.8wt% of a silicone elastomer (Gelest, EXsil 100,100) and 4wt% of ammonium phosphate (Merck) and 1.2wt% of dipentaerythritol (Merck) as a flame retardant was used.

Example 3

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that the thicknesses of the aerogel layer and the coating layer were adjusted. It was found that the total thickness of the insulating sheet for a battery was 3mm, the thickness of the aerogel layer was 2.6mm, and the thickness of the coating layer was 0.2mm.

Example 4

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that the thicknesses of the aerogel layer and the coating layer were adjusted. It was found that the total thickness of the insulating sheet for a battery was 3mm, the thickness of the aerogel layer was 2.4mm, and the thickness of the coating layer was 0.3mm.

Example 5

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that a coating forming solution including 80wt% polyurethane (PU solution of shenzhen gilan chemical company) and 15wt% ammonium phosphate (Merck) and 5wt% dipentaerythritol (Merck) as flame retardants was used.

Example 6

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that a coating forming solution including 97.6wt% polyurethane (PU solution of shenzhen gilan chemical company) and 1.8wt% ammonium phosphate (Merck) and 0.6wt% dipentaerythritol (Merck) as flame retardants was used.

Example 7

An insulating sheet for a battery was manufactured in substantially the same manner as in example 1, except that a coating forming solution including 94.8wt% of polyurethane (PU solution of shenzhen gilan chemical company) and 4.0wt% of monoammonium phosphate and 1.2wt% of dipentaerythritol (Merck) as a flame retardant was used.

Example 8

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that a coating forming solution including 95wt% polyurethane (PU solution of shenzhen gill chemical company) and 5wt% ammonium hydroxide (Merck) as a flame retardant was used.

Comparative example 1

An insulating sheet for a battery was manufactured in substantially the same manner as in example 1, except that an aerogel layer on the surface of which no coating was formed was used. The total thickness of the aerogel layer of the insulating sheet for a battery manufactured was found to be 3mm.

Comparative example 2

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that a coating forming solution including 100wt% of polyurethane (PU solution, shenzhen gill chemical company) was used.

Comparative example 3

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that a coating forming solution including 84.8wt% polyurethane (PU solution of shenzhen gilan chemical company), 4wt% ammonium phosphate (Merck) and 1.2wt% dipentaerythritol (Merck) as flame retardants, and 10wt% fumed silica as a filler was used.

Comparative example 4

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that the coating layer was formed only on the upper surface of the aerogel layer, whereby the thickness of the aerogel layer was 2.7mm and the thickness of the coating layer in the thickness direction was 0.3mm.

Fig. 3 is a schematic view showing the structure of an insulating sheet for a battery according to comparative example 4.

Referring to fig. 3, an insulating sheet 100 for a battery is formed to have a structure including an aerogel layer 110 and a coating layer 120 formed on an upper surface of the aerogel layer.

Comparative example 5

An insulating sheet for a battery was manufactured using substantially the same method as in example 1, except that the coating layer was formed only on the boundary side surface between the upper surface and the lower surface of the aerogel layer, whereby the thickness of the aerogel layer in the thickness direction was 3mm.

Fig. 4 is a schematic view showing the structure of an insulating sheet for a battery according to comparative example 5.

Referring to fig. 4, an insulating sheet 100 for a battery is formed to have a structure including an aerogel layer 110 and a coating layer 120 formed on a boundary side surface between an upper surface and a lower surface of the aerogel layer.

Experimental example

Experimental example 1 evaluation of characteristics of coating

The elastic modulus of the coating layer of each insulating sheet for a battery manufactured in examples 1 to 8 and comparative examples 1 to 5 was evaluated.

The elastic modulus was measured according to ASTM D882 and the results are shown in tables 1 and 2 below.

Experimental example 2 evaluation of characteristics of insulating sheet for Battery

1. Evaluation of thermal insulation

Each of the insulating sheets manufactured in examples 1 to 8 and comparative examples 1 to 5 was evaluated for thermal insulation.

Each insulating sheet was placed between a pair of opposing 1T thick aluminum plates and placed on a hot press. The upper plate of the press was heated to 350 ℃ and the lower plate of the press was not heated and maintained at the starting temperature of 40 ℃. Subsequently, a pressure of 20kN was applied to the lower plate of the hot press, and the highest temperature of the lower plate of the hot press was measured for 11 minutes. The results are shown in tables 1 and 2 below.

2. Evaluation of compressibility

Each of the insulating sheets manufactured in examples 1 to 8 and comparative examples 1 to 5 was cut into a size of 140mm×100mm, and its compressibility was evaluated.

The ratio of the thickness measured by a Universal Test Machine (UTM) fixture when a load of 5kN was applied to the thickness measured by the UTM fixture when a load of 40kN was applied was measured. The results are shown in tables 1 and 2 below.

3. Evaluation of flame retardancy

The flame retardancy of each of the insulating sheets manufactured in examples 1 to 8 and comparative examples 1 to 5 was evaluated.

Flame retardancy was evaluated according to the UL-94V flame retardancy test (UL-94V test (vertical burning test)) method, rated as V-0, V-1 and V-2, and the results are shown in tables 1 and 2 below.

4. Evaluation of dust formation

The dust formation property of each of the insulating sheets manufactured in examples 1 to 8 and comparative examples 1 to 5 was evaluated.

The dust formation was evaluated by measuring the weight loss by vibration evaluation. A 140mm×100mm sample was vibrated at 30Hz for 1 hour using a vibration evaluation apparatus, and the weight loss was measured by the following equation 1.

[ Equation 1]

Weight loss = (sample weight before vibration evaluation-sample weight after vibration evaluation)/sample weight before vibration evaluation ×100

The results are shown in tables 1 and 2 below. When the weight loss is less than 1wt%, the dust forming property of the insulating sheet is evaluated as good, and when the weight loss is 1wt% or more, the dust forming property of the insulating sheet is evaluated as poor.

TABLE 1

TABLE 2

In Table 2 above, NG means the evaluation result that does not satisfy the V-2 rating.

Referring to tables 1 and 2 above, it can be seen that comparative example 1 (in which the thickness of the aerogel layer was 3 mm) has higher thermal insulation than examples 1 to 8, but compressibility and dust formation are reduced due to the absence of the coating layer. In comparative example 2 (in which the flame retardant was not included in the coating layer), flame retardancy could not be ensured. In comparative example 3, in which 10wt% of the filler was included in the coating layer, the elastic modulus of the coating layer was greatly increased, and the compressibility of the insulating sheet was greatly reduced. In comparative example 4, in which the coating layer was formed only on the upper and lower surfaces of the aerogel layer, dust formation was reduced. In comparative example 5 (in which the coating layer was formed only on the boundary side surface of the aerogel layer), the compressibility was lowered.

Thus, it can be seen that the insulating sheet for a battery according to example embodiments has desirable, improved or advantageous thermal insulation, compressibility, flame retardancy, and dust formation.

As is apparent from the above description, the insulating sheet for a battery according to example embodiments may have desired, improved, or advantageous thermal insulation, fire resistance, and flame retardancy or nonflammability, thereby possibly reducing or suppressing heat and flame propagation in a battery cell to a battery cell adjacent thereto due to thermal runaway of the battery cell.

The insulating sheet for a battery according to example embodiments may have desired, improved, or advantageous compressibility, mechanical strength, and dimensional stability, and may reduce or prevent the aerogel layer from falling off due to external impact, thereby being capable of improving workability and reducing or preventing contamination of instruments.

While the foregoing describes example embodiments, the present disclosure is not limited thereto, and it is contemplated that various modifications may be made within the scope of the claims, detailed description of example embodiments, and the accompanying drawings, which also fall within the scope of the present disclosure.

Claims

1. An insulating sheet for a battery, the insulating sheet comprising:

an aerogel layer comprising aerogel, and

A coating configured to cover the entire surface of the aerogel layer, wherein

The coating comprises a flexible polymer and a flame retardant dispersed in the flexible polymer, and

The coating has an elastic modulus of 8MPa or less as measured according to ASTM D882.

2. The insulation sheet of claim 1, wherein the aerogel has a BET specific surface area in the range of 500m ²/g～1,000m²/g.

3. The insulation sheet of claim 1, wherein the aerogel layer further comprises a fibrous support and a functional material comprising at least one of a binder and a dispersant.

4. The insulating sheet of claim 3, wherein said fiber support comprises at least one of natural fibers, silica fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers.

5. The insulating sheet of claim 3 wherein said binder comprises an aqueous polymer binder.

6. The insulating sheet of claim 3, wherein the dispersant comprises at least one of a surfactant, a silane coupling agent, and a phosphate salt.

7. The insulating sheet of claim 3, wherein the aerogel is included in a range of 10wt% to 90wt%, the fiber support is included in a range of 5wt% to 70wt%, and the functional material is included in a range of 0.5wt% to 20wt%, based on the total amount of the aerogel layer.

8. The insulating sheet of claim 1, wherein the flexible polymer comprises at least one of a fluorinated polymer, a polyurethane-based polymer, a polyolefin-based polymer, and a silicone-based polymer.

9. The insulating sheet of claim 1, wherein the flame retardant comprises at least one of an inorganic flame retardant, a phosphorus-based flame retardant, a nitrogen compound-based flame retardant, a silicone-based flame retardant, a melamine-based flame retardant, a halogen-based flame retardant, and a polyol-based flame retardant.

10. The insulating sheet of claim 1, wherein the flame retardant comprises at least one of a phosphorus-based flame retardant and a polyol-based flame retardant.

11. The insulating sheet of claim 10, wherein the flame retardant comprises a phosphorus-based flame retardant and a polyol-based flame retardant in a weight ratio in a range of 1:0.1 to 1:0.5.

12. The insulating sheet of claim 1, wherein the content of the flame retardant is in the range of 1wt% to 25wt%, based on the total amount of the coating layer.

13. The insulating sheet of claim 1, wherein the coating does not include a filler.

14. The insulating sheet of claim 1, wherein the thickness of the coating layer is 20% or less of the total thickness of the insulating sheet for a battery.

15. The insulating sheet of claim 1, wherein

The flexible polymer includes at least one of a polyurethane-based polymer and a silicone-based polymer, and

The flame retardant includes at least one of a polyol flame retardant and a phosphorus flame retardant.

16. A method of manufacturing an insulating sheet for a battery, the method comprising:

forming an aerogel layer comprising aerogel, and

Forming a coating layer to cover the entire surface of the aerogel layer, wherein

17. A battery module, comprising:

a plurality of battery cells, and

An insulating sheet according to any one of claims 1 to 15 or an insulating sheet manufactured according to the method of claim 16 between the plurality of battery cells.